JP2979824B2 - Crane steady rest control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling the swing of a suspended crane.

[0002]

2. Description of the Related Art A suspended load is suspended from a traveling body provided on a predetermined route provided on a ceiling or the like so as to be capable of traveling, and the suspended body is moved to an arbitrary position by traveling of the traveling body. 2. Description of the Related Art In a suspended crane such as an overhead crane configured to be transported, automatic operation for automatically transporting a suspended load to a target position has been promoted.

In order to automate the operation of such a crane, it is important to suppress the swing of the suspended load at the time of stopping at the target position and to improve the positioning accuracy of the suspended load. Conventional control methods for automatic operation of a crane are roughly classified into two types of control methods, a program control method and a feedback control method.

The above-mentioned program control method is based on a phase plane locus diagram showing a relationship between a swing angle and a swing angular velocity of a pendulum motion of a suspended load when a crane is operated. The speed pattern of the traveling body is determined in advance, and the speed of the traveling body is controlled to follow the speed pattern. In such a program control method, the response delay of the speed control system of the traveling body or the like causes
There is a drawback that the speed pattern cannot be realized, and as a method for solving this drawback, for example, there is a control method for correcting the speed switching timing in the speed pattern based on the response delay or the like that can be known in advance. (Japanese Patent Publication No. 63-64393).

Further, as the feedback control method, for example, the swing angle and the swing angular velocity are detected, the suspension length of the rope is adjusted based on the detection results, and the swing angle is reduced to perform the steadying. There is a control method (JP-A-60-202083).

[0006]

However, in the apparatus using the conventional program control method as described above, the swing should theoretically be eliminated at the target position, but the speed pattern when actually performing the control is as follows. Since the main purpose is to improve cargo handling efficiency, the acceleration set during acceleration / deceleration is large, so that the speed control system of the traveling body cannot follow the speed pattern with high responsiveness, and in actual control, Even if the speed is made to follow the speed pattern, the speed pattern becomes ineffective due to various disturbances, and there is a problem that a residual shake occurs at the target position for such a reason.

Further, in the apparatus using the conventional feedback control method as described above, when adjusting the suspension length, there is a problem that the suspended load may collide with an obstacle depending on the state of the space below the traveling route of the crane. was there.

The present invention has been made in view of such circumstances, and has as its object to provide a crane steady rest control device that realizes stable automatic operation of a crane.

[0009]

SUMMARY OF THE INVENTION A crane steady rest control device according to the present invention is a suspension type crane steady rest control device which performs steady rest control of a suspended load by controlling the traveling speed according to a speed pattern. Means for determining a basic speed pattern consisting of an acceleration region, a high constant speed region, a first deceleration region, a low constant speed region, and a second deceleration region for a period from the start to the stop of the crane; Means for detecting the vibration of the suspended load, maximum value detection means for detecting the maximum value of the vibration detected by the means, timing detection means for detecting the timing at which the maximum value of the vibration is detected, Means for detecting a position; means for determining a distance from a detected position of the crane to a scheduled stop position at the timing detected by the timing detecting means; Based detection result of the detection result of the maximum value of deflection at the maximum value detecting means, and you to zero the amplitude of the suspended load at the expected stop position in the second reduction zone
Of the crane traveling acceleration to be switched to
Means, a means for obtaining a final speed pattern based on the obtained accelerations of the plurality of stages, and a control of the traveling speed according to the basic speed pattern until the timing at which the maximum value of the shake is detected by the timing detecting means, Means for controlling the traveling speed in accordance with the final speed pattern after the timing at which the maximum value of the shake is detected by the timing detecting means.

[0010]

When the traveling speed of the crane is controlled in accordance with a speed pattern set so as to sufficiently suppress the steadying of the suspended load, even if the traveling speed satisfactorily follows the speed pattern, various types of control are performed during the control. In some cases, the disturbance of the suspended load cannot be suppressed due to disturbance. However, in the present invention, in the second deceleration region before the crane stops, the distance from the current position of the crane to the expected stop position and the maximum value of the suspended load swing based on bets, a plurality of stages so as to zero the amplitude of the suspended load at the scheduled stop position
The final speed pattern is obtained by calculating the crane traveling acceleration of
Because this is therefore the control of the running speed is made, the deflection of the suspended load by the disturbance is suppressed. Further, the speed control in the second deceleration region is a control after the speed of the speed pattern is reduced to the low constant speed region, and there is no need to perform abrupt deceleration, so that the speed control can be performed with high followability. , And stable control can be performed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. First, the principle of the steady rest control method in the crane steady rest control device according to the present invention (hereinafter referred to as the present device) will be described.

FIG. 1 is a schematic side view of a crane for explaining the basic principle of the apparatus of the present invention. In the figure, reference numeral 1 denotes a suspension type crane. The crane 1 suspends a suspended load 3 by a rope 2 suspended below the crane 1, and drives a wheel 11 provided at a lower portion of the crane 1 so as to indicate a hollow arrow in the figure. It moves horizontally in the direction indicated by.

The model formulas of the pendulum in such a crane 1 are shown in the following formulas (1) to (3).

[0014]

(Equation 1)

[0015]

(Equation 2)

[0016]

(Equation 3)

The above equation (1) can be transformed into the following equation (4).

[0018]

(Equation 4)

Equation (4) indicates that when the crane 1 is accelerated or decelerated at a constant acceleration α, the shake state is centered on (α / ω, 0) on the phase plane represented by (ωx, dot x). Represents a circular locus. Therefore, if there is no vibration at the start of acceleration, the vehicle is accelerated at a constant acceleration α for a period T, travels at a maximum speed according to the distance to the target position, and is decelerated and stopped at a constant acceleration −α during the period T. In principle, no swing remains in principle.

However, in such a control method of accelerating and decelerating at a constant acceleration (corresponding to a conventional program control method), although the deflection does not remain in principle at the timing of reaching the target position, the speed corresponding to the crane speed command is Residual run-out occurs due to followability, accuracy of the run-out period calculated from the effective rope length, and other disturbances during the execution of various controls.

Therefore, in the present invention, the crane 1 is moved in a speed pattern as shown in FIG. FIG. 2 is a graph showing the speed pattern of the crane in the apparatus of the present invention, in which the vertical axis represents speed and the horizontal axis represents time, and these relationships are shown.

The speed pattern of FIG. 2, the acceleration range a ₁ of the acceleration at a constant acceleration, the higher speed range a ₂ to perform holding of the high speed constant velocity, first reduction zone for performing deceleration at a constant acceleration becomes more and a _3, a first speed pattern a such a speed pattern of the conventional program control method, a low constant speed zone b ₁ for moving the crane 1 with a predetermined time constant low speed, the crane 1 subsequent thereto a speed pattern obtained by adding the second speed pattern b made more a deceleration zone b ₂ to stop decelerating at the final speed pattern will be described later, in the present invention, such a speed pattern, determined in advance as a basic speed pattern.

By executing the basic speed pattern, the vibration generated during the execution of the first speed pattern a is reduced and eliminated during the execution of the second speed pattern b, and the positioning accuracy is improved. .

As described above, since the first speed pattern a is the same as the speed pattern in the conventional program control method, the description thereof is omitted, and the first constant speed pattern b will be described below. The final speed pattern after ₁ will be described.

FIG. 3 is a graph showing a final speed pattern, in which the vertical axis represents speed and the horizontal axis represents time, and these relationships are shown. The conditions necessary for controlling the final speed pattern are that the crane 1 stops when the crane 1 reaches the target position and that the suspended load 3 does not swing. Therefore, the control is
The following three constraints must be satisfied: the mileage constraint expressed by the following equation (5), the stop constraint expressed by the following equation (6), and the seismic restraint expressed by the following equation (7). As a prerequisite, the acceleration of the crane 1 is switched to three stages of γ ₁ , γ ₂ , and γ ₃ every half cycle (T / 2) of the swing of the suspended load 3, and the 3/2 cycle (3T / 2) to complete the control.

[0026]

(Equation 5)

[0027]

(Equation 6)

[0028]

(Equation 7)

The travel distance constraint condition in the above equation (5) is that the accelerations γ ₁ , γ ₂ , γ _{3 and} the sum of the travel distances in the respective sections of the accelerations γ ₁ , γ ₂ , γ ₃ are the control of the final speed pattern. Distance L from start point to target position (area of hatched area in FIG. 3)
It means that you have to become. In addition,
The stop constraint condition in equation (6) is that the velocity must become zero in 3/2 cycles (3T / 2) of the swing of the suspended load 3 as a result of deceleration by the accelerations γ ₁ , γ ₂ , γ _3. Represents.

In addition, the anti-vibration constraint condition of the above equation (7) is that, as a result of deceleration by the accelerations γ ₁ , γ ₂ , γ ₃ , the vibration of the suspended load 3 is 3/2 cycles (3T / 2). Indicates that it must disappear. The anti-shake constraint is represented by a phase plane locus diagram in FIG. FIG. 4 is a phase plane locus diagram showing the relationship between the amplitude (ωx) and the shake angular velocity (dot x) according to the final speed pattern. The vertical axis shows the shake angular velocity (dot x), and the horizontal axis shows the amplitude (ωx). Is shown.
In FIG. 4, the acceleration is switched to three stages, γ ₁ , γ ₂ , and γ ₃ , so that the start point A of the deceleration section at the acceleration γ ₁ is changed from the start point B of the deceleration section at the acceleration γ ₂ to the acceleration γ ₃ through the starting point C of the deceleration zone with the shake to the end point of the deceleration zone of the acceleration gamma ₃ D (origin) it can be seen that attenuated spirally.

When the accelerations γ ₁ , γ ₂ , and γ ₃ are obtained by using the equations (5), (6), and (7) as simultaneous equations, the results are as shown in the following equations (8) to (10). .

[0032]

(Equation 8)

[0033]

(Equation 9)

[0034]

(Equation 10)

The accelerations γ ₁ , γ ₂ , and γ ₃ satisfying the above three constraints thus obtained are set to a half cycle (T /
2) By switching every time, the crane 1 stops when the crane 1 reaches the target position, and the vibration control can be performed so that the residual vibration of the suspended load 3 does not occur.

Next, the structure of the anti-shake control device for performing the anti-shake control as described above will be described. FIG. 5 is a schematic block diagram showing the configuration of the anti-shake control device according to the present invention.

The rotating force of the motor 6 is applied to the wheels 11 of the crane 1 via the rotating force transmitting mechanism 7, and the crane 1 is driven by the driving of the wheels 11 by the rotating force. The suspended amount of the rope 2 of the crane 1 is
The suspension amount is controlled by the suspension amount control device 9.

Reference numeral 4 in the drawing denotes a basic speed pattern calculation device for calculating the basic speed pattern and calculating the shake period as shown in FIG. This basic speed pattern calculation device 4
Then, based on the information on where the suspended load is to be transported from where to where, the obstacle avoidance conditions, the speed constraint and the acceleration constraint of the crane 1 are taken into consideration, and the basic speed pattern is obtained by calculation, and the basic speed pattern is obtained. the calculated period T deflection from the effective rope length L _R, based on the weight and size of the suspension length and the suspended load 3 or the like, gives the stop control unit 5 vibration information of these calculation results. Here, the low constant velocity region speed V _LOW ,
The period T is provided from the basic speed pattern calculation device to the anti-shake control device 5 together with the basic speed pattern.

The anti-shake control device 5 includes a speed pattern determination device 51, a final speed pattern calculation device 52, and a speed control device 53.
And the basic speed pattern calculation device 4
Is given to the speed pattern determination device 51.
In addition to this, a final speed pattern is given to the speed pattern determining device 51 from the final speed pattern calculating device 52 at a timing described later.

The speed / position detecting device 8 for detecting the traveling speed and the current position of the crane 1 by measuring the number of rotations at which the rotational force transmission mechanism 7 drives the wheels 11 is provided to the final speed pattern calculating device 52. Information on the detection result is provided, and information on the detection result is provided from a shake detection device 10 that detects the shake of the suspended load 3.

In the final speed pattern calculation device 52, the speed
Based traveling speed given from the position sensor 8 and the detection data of the current position, the crane 1 is to determine whether the entered low constant speed region b ₁ of the second speed pattern b in the basic speed pattern, further shake The timing at which the shake becomes maximum is detected based on the detection data of the detection device 10.
Then, at the above timing, the final speed pattern is calculated using the above-described equations (8), (9), and (10), and the calculation result is provided to the speed pattern determination device 51.

In the speed pattern determination device 51, the traveling speed of the crane 1 is adjusted so that the traveling speed of the crane 1 follows the basic speed pattern based on the information on the basic speed pattern given from the basic speed pattern calculation device 4. When the command information is provided to the speed control device 53 and the final speed pattern information is provided from the final speed pattern calculation device 52, the information and the swing period information provided from the basic speed pattern calculation device 4 are used. Is provided to the speed control device 53 on the basis of the traveling speed of the crane 1 so that the traveling speed of the crane 1 follows the final speed pattern.
In addition, the speed pattern determination device 51 uses the crane 1
Before the start of traveling, a command value of the suspended amount is given to the suspended amount control device 9.

To the speed control device 53, in addition to the above speed command, detection data of the traveling speed is given from the speed / position detecting device 8. The speed control device 53 supplies a control signal to the motor 6 so that the detection data of the traveling speed matches the speed command.

Next, the operation of the anti-shake control device configured as described above will be described. However, among the basic speed patterns,
Since the first speed pattern a performs the same control as the speed pattern in the conventional program control method, the description thereof is omitted, and the control of the second speed pattern b after the low uniform speed region will be described.

FIG. 6 is a flowchart of the anti-shake control. First, the final speed pattern calculation device 52
It is determined whether or not reached the low constant speed zone b ₁ (step
S1), after determination of the arrival of the low constant speed zone b _1, performs a shake detection (step S2), and shake detects the timing at which the maximum (step S3). As a method of detecting the timing, a method is used in which the detection data of the shake is stored several times, and a method of detecting that the detection data is switched from increase to decrease or from decrease to increase is used. In this detection method, the detection timing is delayed by one detection time from the timing at which the shake becomes maximum, but the detection time is sufficiently short, so there is no particular problem.

Next, the final speed pattern calculation device 52 detects the position of the crane 1 at the detection timing (step S4), and calculates the remaining distance to the target position based on the detection result (step S4). S5). Then, a final speed pattern is calculated by using the above-mentioned equations (8), (9), and (10) (step S6), and the calculation result is used as a speed pattern determination device.
Given to 51.

Next, the speed pattern determining device 51 and the speed control device 53 control the speed of the motor 6 according to the final speed pattern calculated by the final speed pattern calculating device 52, and control the traveling speed of the crane 1. (Step S7)
Finally, the crane 1 is stopped at the target position.

Next, a description will be given of the result of actually performing the steady rest control using the steady rest control device of the crane having the above configuration. In this control, the crane 1
Maximum speed 1.5 m / sec, with the largest acceleration 0.4 m / sec ^2, the distance of the speed in the low constant speed range 0.15 m / sec, from the starting point P ₁ of the low constant speed range to the target position P ₂ 3 m.

FIGS. 7A and 7B show the control results. FIG. 7 is a time chart showing the control result.
FIG. 7 (a) shows the time transition of the speed, acceleration and traveling distance of the crane 1 under control, and FIG. 7 (b) shows the time transition of the swing amplitude of the suspended load 3 under control. . As is clear from FIG. 7, the amplitude of the suspended load 3 becomes zero at the target position P _2, the residual vibration is eliminated.

[0050]

In the present invention apparatus as described above in detail, according to the present invention, in the second reduction zone before stopping the crane, Toka maximum deflection distance and the suspended load from the current position of the crane to the stop position
Et al., Double determined so as to zero the amplitude of the suspended load at stop position
Final speed pattern based on several stages of crane travel acceleration
Look, since this thus control the travel speed is performed,
The swing of the suspended load due to the disturbance is suppressed, and the residual swing of the suspended load at the stop position can be eliminated. In addition to this, the speed control in the second deceleration range is control after the speed of the speed pattern has been reduced to the low constant speed range, and there is no need to perform abrupt deceleration. Can be executed, and stable anti- sway control can be executed , improving safety
For example , the present invention has an excellent effect of realizing stable automatic operation of the crane.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a crane for explaining the basic principle of the device of the present invention.

FIG. 2 is a graph showing a crane speed pattern in the apparatus of the present invention.

FIG. 3 is a graph showing a final speed pattern.

FIG. 4 is a phase trajectory diagram of the relationship between the amplitude and the shake angular velocity according to the final velocity pattern.

FIG. 5 is a schematic block diagram showing the configuration of the device of the present invention.

FIG. 6 is a flowchart of anti-shake control.

FIG. 7 is a time chart showing a control result when the steady rest control is actually performed using the apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crane 3 Suspended load 4 Basic speed pattern calculation device 5 Sway control device 8 Speed / position detection device 9 Runout detection device 51 Speed pattern determination device 52 Final speed pattern calculation device 53 Speed control device

Claims (1)

(57) [Claims] An apparatus for controlling the suspension of a suspended crane, which controls the steadying of a suspended load by controlling the traveling speed of the crane according to a speed pattern, comprising: Means for determining a basic speed pattern consisting of a high uniform speed region, a first deceleration region, a low constant speed region, and a second deceleration region; a unit for detecting a swing of a suspended load in the low constant speed region; Maximum value detecting means for detecting the maximum value of the shake, timing detecting means for detecting the timing at which the maximum value of the shake is detected, means for detecting the position of the crane, and timing detected by the timing detecting means. Means for calculating the distance from the detection position of the crane to the expected stop position in the crane; Based on the results and, to be order to zero the amplitude of the suspended load at the expected stop position in the second reduction zone
Hand to find multiple stages of crane running acceleration to be switched
Step, means for obtaining a final speed pattern based on the obtained accelerations of the plurality of steps, and controlling the traveling speed according to the basic speed pattern until the timing at which the maximum value of the shake is detected by the timing detecting means, Means for controlling the traveling speed in accordance with the final speed pattern after the timing at which the maximum value of the run-out is detected by the timing detecting means.